Hannaea inaequidentata, girdle view, SEM 35 colony with ca. 5 frustules 36 colony with two frustules 37 detail of Fig. 1, showing epivalves and hypovalves, distinct mantle plaques, fork-shaped interlocked linking spines at valve middle (arrowheads) and more acute spines towards each apex; note 4:2 configuration of girdle bands in three normal but not dividing vegetative frustules. Scale bars: 10 μm (35, 36), 5 μm (37).